Proceedings of National Academy of Sciences, USA, 74: 5,463 to 5,467 (1977) describes a dideoxy method as a method for analyzing a base sequence of a nucleic acid. In addition, Japanese Patent Application Laid-Open No. H05-168500 describes a method of determining a base sequence of a nucleic acid by using the dideoxy method.
However, the above described method of analyzing the base sequence by using the dideoxy method includes a step of separating the extended DNA strands by electrophoresis, and accordingly needs a long period of time for obtaining an analysis result.
In addition, Japanese Published Patent Application No. 2003-189899 describes a method of detecting a base sequence of a nucleic acid, by carrying out a reaction between a target single-standard nucleic acid, a single-stranded nucleic acid probe immobilized on a substrate, DNA polymerase and labeled ddNTP, where the probe is hybridizable with a downstream nucleotide sequence of an SNP site in the single-stranded nucleic acid. However, the above described detecting method has problems that the method needs to wash out the unreacted labeled ddNTP and only one base is identified. Accordingly, the present invention provides a polymerase-immobilized electrode of highly sensitive detection ability, and a method for obtaining the information on a base sequence by using the polymerase-immobilized electrode.